The crossword solutions for the term IRIS, LAYER OF THE are UVEA, which is a four letter word. UVEA is the middle layer of the eye, also known as the uveal tract or uveal coat. It consists of the iris, ciliary body, and choroid. The iris is the colored part of the eye that controls the amount of light entering the eye. The ciliary body is responsible for producing the aqueous humor, which helps to maintain the shape of the eye. The choroid is a layer of blood vessels that provides oxygen and nutrients to the retina. Together, these three layers make up the uvea, which is essential for vision.